Communicable Diseases Surveillance consists of data from various sources. The National Notifiable Diseases Surveillance System (NNDSS) is conducted under the auspices of the Communicable Diseases Network Australia New Zealand. The Virology and Serology Laboratory Reporting Scheme (LabVISE) is a sentinel surveillance scheme. The Australian Sentinel Practice Research Network (ASPREN) is a general practitioner-based sentinel surveillance scheme. In this report, data from the NNDSS are referred to as 'notifications' or 'cases', whereas those from ASPREN are referred to as 'consultations' or 'encounters' while data from the LabVISE scheme are referred to as 'laboratory reports'.

Vaccine preventable diseases

Meningococcal disease

There have been 193 notifications of meningococcal disease so far this year. This is an overall increase of 40 notifications for the same reporting period in 1998 (Table 1).

Sixty two per cent of these notifications were from males. Most notifications were in the 0-4 age group (Figure 1). Higher rates of meningococcal disease were evident in males in most age groups compared to females. The peak month of onset of meningococcal disease is usually August (Figure 2).

Table 1. Notifications of meningococcal disease, States and Territories, Jan-June 1998 and 1999

ACT

NSW

NT

Qld

SA

Tas

Vic

WA

Aust

1998

1

66

5

36

5

4

22

19

158

1999

0

83

5

29

8

6

39

23

193

Figure 1. Notifications of meningococcal disease, January - June 1999, by age group and sex

Measles

The number of measles notifications remains low, with the outbreak among young adults in Victoria confirmed as having ended. With the end of this outbreak notifications for measles have returned to the low figures seen in December 1998 (Figure 2).

Arboviruses

Ross River virus

Although a higher than normal number of notifications for Ross River virus infection has been reported (2,777 this year to date), the very high number of cases seen in 1992 (approximately 5,800) and 1996 (approximately 7,850) is not expected. Further investigation of the notifications for the year to date show that the number of notifications is beginning to decline in line with the usual annual cycle of a greater number of cases during the warmer months of the year.

This article was published in Communicable Diseases Intelligence Volume 23, No 7, 8 July 1999.